Bug 1582192 - add a job to build a wasi sysroot; r=glandium

When we start compiling things to wasm during the build process, we're
going to need a basic sysroot.  This new job builds just such a sysroot.

Differential Revision: https://phabricator.services.mozilla.com/D50993

--HG--
extra : moz-landing-system : lando

taskcluster/ci/fetch/toolchains.yml

@@ -415,6 +415,13 @@ clang-9:
         repo: https://github.com/llvm/llvm-project
         revision: 0399d5a9682b3cef71c653373e38890c63c4c365
 
+wasi-libc:
+    description: wasi-libc source code
+    fetch:
+        type: git
+        repo: https://github.com/CraneStation/wasi-libc
+        revision: c35f0f5dd64ad982bbad71f3e3a8942a1029c1e6
+
 ninja:
     description: ninja 1.9.0
     fetch:

taskcluster/ci/toolchain/misc.yml

@@ -158,6 +158,20 @@ browsertime:
         toolchain:
             - linux64-node
 
+wasi-sysroot:
+    description: "wasi sysroot build process"
+    treeherder:
+        symbol: TL(wasi-sysroot)
+    run:
+        script: build-wasi-sysroot.sh
+        sparse-profile: null
+        toolchain-artifact: public/build/wasi-sysroot.tar.xz
+    fetches:
+        fetch:
+            - wasi-libc
+        toolchain:
+            - linux64-clang
+
 wrench-deps:
     description: "Downloads all the crates needed for building wrench"
     treeherder:

taskcluster/scripts/misc/build-wasi-sysroot.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+set -x -e -v
+
+# This script is for building libc-wasi.
+
+cd $GECKO_PATH
+
+# gets a bit too verbose here
+
+cd $MOZ_FETCHES_DIR/wasi-libc
+make WASM_CC=$MOZ_FETCHES_DIR/clang/bin/clang \
+     WASM_AR=$MOZ_FETCHES_DIR/clang/bin/llvm-ar \
+     WASM_NM=$MOZ_FETCHES_DIR/clang/bin/llvm-nm \
+     SYSROOT=$(pwd)/wasi-sysroot
+
+# Put a tarball in the artifacts dir
+mkdir -p $UPLOAD_DIR
+tar caf $UPLOAD_DIR/wasi-sysroot.tar.xz wasi-sysroot